Cervical cytopathology. An evaluation of its accuracy based on cytohistologic comparison

A comprehensive review of anal cancer-with a special focus on anal cytology

The diagnosis of anal cancer is relatively uncommon, but its incidence has been steadily increasing in high-risk populations. In the 2001 Bethesda System for Reporting Cervical Cytology, anal cytology was introduced as a component. Since then, it has been recognized as a potential tool for screening anal cancer, often in conjunction with high-resolution anoscopy. There are notable similarities between anal cancer and cervical cancer, including the causative role of human papillomavirus. However, there are also significant differences, particularly in terms of disease prevalence. Anal cytology may be used as a primary screening test, and in the event of abnormalities, patients are subsequently directed for high-resolution anoscopy. However, the best approach for anal cancer screening is yet to be determined and uniformly implemented. This comprehensive review article provides an in-depth analysis of the epidemiology and incidence of anal precursor and malignant lesions. It explores the various methods of sample procurement, preparation, interpretation (including sensitivity and specificity), and reporting terminology in anal cytology. The article also addresses the significance of concurrent high-risk human papillomavirus screening in anal cytology and its role in screening programs. Furthermore, it discusses the follow-up, prevention, and subsequent management strategies for anal cancers. By synthesizing current knowledge in these areas, this review aims to provide a comprehensive understanding of anal cytology and its implications in the early detection, prevention, and management of anal neoplasia and cancer.

Progress in Fourier Transform Infrared Spectroscopic Imaging Applied to Venereal Cancer Diagnosis

Fourier transform infrared imaging spectroscopy is a powerful technique that provides molecular and spatial information at the single-cell level. We report on the progress of this technology in the field of cancer research, focusing on human cervical cancer because of the inherent difficulty in grading this type of cancer and as a model for venereal cancers in dogs. Using a suite of multivariate imaging processing techniques, we demonstrate the potential of this technique to identify histologic features in the normal epithelium and cervical intraepithelial neoplasia stages I and III. We highlight the advantages and detail the barriers that need to be overcome before implementation of this technology in the clinical environment.

Relative accuracy of cervical and anal cytology for detection of high grade lesions by colposcope guided biopsy: a cut-point meta-analytic comparison

Background

We recently reported, using a receiver operating characteristic area metric, the first meta-analytic comparison of the relative accuracy of cervical and anal cytology in detecting moderate or severe histopathologic lesions by magnification directed punch biopsy. The aim of the present research was to meta-analytically examine cut-point specific operating characteristics (sensitivity, specificity) of cervical and anal cytology in detecting high grade squamous intraepithelial lesion (HSIL) histopathology by colposcope directed punch biopsy.

Methodology/Principal Findings

The primary eligibility requirement was availability of tabulated cytology (normal, atypical cells of unclear significance [ASCUS], low grade squamous intraepithelial lesion, HSIL or atypical squamous cells cannot rule out high grade [ASC-H]) and biopsy (<HSIL, ≥ HSIL) counts. Meta-analysis and meta-regression of diagnostic accuracy was performed with examination of study quality criteria and heterogeneity. Thirty-three cervical and 11 anal publications were eligible between 1990 and 2010. Meta-analytically cut-point analysis showed that using a cut-point of ASCUS the sensitivity in both settings is similar while anal cytology is less specific than cervical cytology (specificity [95% confidence interval] 0.33 [0.20–0.49] vs. 0.53[0.40–0.66], p = 0.04) for the detection of HSIL histopathology by colposcope directed punch biopsy.

Conclusions/Significance

Using a cytology cut-point of HSIL or ASC-H, anal cytology is less sensitive but comparably specific to cervical cytology. However, using a cut-point of ASCUS, differences in accuracy were of borderline significance.

Comparative accuracy of anal and cervical cytology in screening for moderate to severe dysplasia by magnification guided punch biopsy: a meta-analysis

Background

The accuracy of screening for anal cancer precursors relative to screening for cervical cancer precursors has not been systematically examined. The aim of the current meta-analysis was to compare the relative accuracy of anal cytology to cervical cytology in discriminating between histopathologic high grade and lesser grades of dysplasia when the reference standard biopsy is obtained using colposcope magnification.

Methods and Findings

The outcome metric of discrimination was the receiver operating characteristic (ROC) curve area. Random effects meta-analysis of eligible studies was performed with examination of sources of heterogeneity that included QUADAS criteria and selected covariates, in meta-regression models. Thirty three cervical and eleven anal screening studies were found to be eligible. The primary meta-analytic comparison suggested that anal cytologic screening is somewhat less discriminating than cervical cytologic screening (ROC area [95% confidence interval (C.I.)]: 0.834 [0.809–0.859] vs. 0.700 [0.664–0.735] for cervical and anal screening, respectively). This finding was robust when examined in meta-regression models of covariates differentially distributed by screening setting (anal, cervical).

Conclusions

Anal cytologic screening is somewhat less discriminating than cervical cytologic screening. Heterogeneity of estimates within each screening setting suggests that other factors influence estimates of screening accuracy. Among these are sampling and interpretation errors involving both cytology and biopsy as well as operator skill and experience.

[Correlation of cervical cytology and histology]

A lack of correlation of cytological diagnoses with subsequent histological tissue diagnoses in cervical pathology is caused by either sampling or by interpretation errors. The term sampling error refers to both obtaining cytological material by a cervical smear as well as obtaining tissue samples by surgical procedures such as biopsy or conization. The term interpretation error refers to a lack of correlation as a consequence of the subjective variability in the diagnostic evaluation of cytological, histological or colposcopic findings. This so-called interobserver variability is well known and of considerable significance. Cytological-histological correlation is an important and mandatory method of quality assurance in the cytology laboratory. Lack of correlation can be crucial for the patient because of possible over treatment or under treatment. It can also undermine the relationship between cytopathologists and clinicians. It is therefore crucial to recognize the sources of error presented in this review and to make an effort to resolve discordances by communication and second review.

The value of repeated cytology at the time of first colposcopy: a retrospective analysis of 1,087 cases

Papanicolaou tests are often repeated just before the procedure for women who have been referred for colposcopy. The validity and clinical usefulness of this practice, however, is unclear. We retrospectively assessed the value of repeated cytology in a cohort of 1,087 consecutive patients who underwent repeated Papanicolaou testing at first colposcopy. The repeated cytology was considered clinically useful if the results could conceivably have influenced the physician's decision about more invasive diagnostic/therapeutic evaluation based on contemporary practice guidelines. Repeated cytology provided potentially clinically useful information in only a small proportion (3.6%) of the cases analyzed overall, including 41% (26/63) and 1.8% of the high- and low-grade squamous intraepithelial lesions referral cytology cases, respectively. Our data indicate that repeated cytology provides potentially clinically useful information in only a small percentage of overall cases but a substantial proportion of high-grade squamous intraepithelial lesion referral cytology cases, suggesting that high-risk referral cytology case subsets can be defined wherein the routine performance of repeated cytology would be most efficacious.

Estimating the accuracy of anal cytology in the presence of an imperfect reference standard

BACKGROUND

The study aim is to estimate sensitivity and specificity of anal cytology for histologic HSIL in analyses adjusted for the imperfect biopsy reference standard.

METHODS AND PRINCIPAL FINDINGS

Retrospective cohort study of an anal dysplasia screening program for HIV infected adults. We estimated the prevalence of histologic HSIL by concurrent cytology category and the associated cytology ROC area. Cytology operating characteristics for HSIL were estimated and adjusted for the imperfect reference standard by 3 methodologies. The study cohort included 261 patients with 3 available measures: (1) referral cytology; (2) HRA cytology; and (3) HRA directed biopsy. The prevalence of biopsy HSIL varied according to the concurrent HRA cytology result: 64.5% for HSIL or ASC-H, 12.6% for LSIL, 10.9% for ASCUS, and 6.3% for no abnormality. The cytology ROC area was 0.78. The observed prevalence of HSIL was 37% (referral cytology), 24% (HRA cytology), and 24% (HRA biopsy). Unadjusted estimates of sensitivity and specificity of cytology were 0.66 and 0.90, respectively. Adjusted estimates varied from 0.47-0.89 (sensitivity) and 0.89-1.0 (specificity).

CONCLUSIONS

Analysis of a single dataset yields widely different estimates of anal cytology operating characteristics that depend on difficult to verify assumptions regarding the accuracy of the imperfect reference standard.

Perianal Condylomas, Anal Squamous Intraepithelial Neoplasms and Screening: A Review of the Literature

Anal squamous intraepithelial lesions (ASILs) are the precursors to anal cancer. Human papillomavirus infection has a direct link to ASIL formation and is responsible for up to 80% of anal cancers. But while much importance has been focused on targeting cancer precursors in the cervix, relatively little concern has been afforded to the anal canal. With the advent of cervical Pap smear screening in various regions, the incidence of cervical cancer has declined. However, marked similarities in the biological and pathological profiles of cervical cancer and anal cancer mean that anal cancer should be preventable in the same way – by curbing the progression of ASIL to cancer. This article explores the literature on ASILs and the growing problem of anal cancer in the community, along with the literature surrounding the current progress towards implementing a screening programme for ASIL in the future.

Screening anal dysplasia in HIV-infected patients: is there an agreement between anal pap smear and high-resolution anoscopy-guided biopsy?

PURPOSE

The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients.

METHODS

We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system ("without dysplasia" and "with dysplasia of any grade"). Estimates were also calculated for the detection of high-grade dysplasia.

RESULTS

During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%.

CONCLUSION

Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.

Screening HIV-infected individuals for anal cancer precursor lesions: a systematic review

Individuals with human immunodeficiency virus (HIV) infection are at increased risk for human papillomavirus-related squamous cell cancer of the anus. Screening HIV-infected patients for squamous cell cancer of the anus and human papillomavirus-related anal dysplasia may prevent excess morbidity and mortality. We have conducted a systematic review of the indirect evidence in the literature regarding the utility of anal Papanicolau (Pap) smear screening of HIV-infected individuals in the highly active antiretroviral therapy era. Although there are no published studies evaluating the efficacy of anal Pap smear screening for preventing squamous cell cancer of the anus or anal intraepithelial neoplasia, we reviewed data regarding the burden of disease, anal Pap smear sensitivity and specificity, the prevalence of anal dysplasia, and 1 cost effectiveness study. The available evidence demonstrates that HIV-infected individuals have an increased risk for squamous cell cancer of the anus and anal intraepithelial neoplasia. This review identifies important areas for further study before routine anal Pap smear screening can be recommended.

Repeating cytology at initial colposcopy does not improve detection of high-grade abnormalities: A retrospective cohort study of 6595 women

OBJECTIVE

To determine if repeating a smear improves detection of high-grade pre-invasive or invasive disease of the cervix compared with women who do not have a repeat smear at the time of the initial colposcopic assessment for referral of an abnormal smear.

DESIGN

Retrospective cohort study.

SETTING

All Wales Colposcopy database.

POPULATION

The cohort included women referred for colposcopy with an abnormal smear result, who were seen between 1st January 2002 and 31st December 2002.

METHOD

The management of the group of women who had a repeat smear was compared with the group who did not have a repeat smear test at their first visit. Confidence interval analysis was used to compare results between the two groups.

MAIN OUTCOME MEASURE

The positive predictive value and sensitivity of the repeat smear to predict outcome, compared to the referral smear in cases where a smear was not repeated at the colposcopy clinic.

RESULTS

3505 cases (54.0%) did not have a repeat smear at initial colposcopy, whereas 2990 (46%) did. There was a significantly higher rate of referral for low-grade dyskaryosis in the group who had repeat smear testing. The median time interval from the referral smear to the first colposcopy was 49 days for both groups. The specificity and positive predictive value for high-grade lesions were significantly higher in the repeat smear results. The sensitivity was significantly lower, and a high-grade lesion would have been missed with the repeat smear in 14.0% of all referrals.

CONCLUSIONS

Colposcopists appeared more inclined to repeat smears for low-grade referrals. The time interval from the referral smear to colposcopy did not appear to influence this decision. A repeat smear test at the first colposcopy visit will detect less high-grade pre-invasive or invasive disease than the initial referral smear.

The comparative diagnostic accuracy of conventional and liquid-based cytology in a colposcopic setting

OBJECTIVE

This study was conducted to compare the performance of liquid-based cytology (LBC) and conventional cytology (CS) in the high prevalence setting of colposcopy clinic.

DESIGN

A split sample of matched ThinPrep (TP) and conventional smear from 563 patients were evaluated blindly. The performance of both techniques was compared with the gold standard of biopsy results or normal colposcopy examination in 441 cases.

SETTING

Colposcopy clinic of an inner city hospital for women and children.

SAMPLE

Five hundred and sixty-three women referred to colposcopy clinic over 14-month period.

METHODS

Cervical smears were taken from 563 women referred for colposcopy. Using the split-sample technique, the material was spread on a conventional (CS) slide and the remaining material rinsed in a PreservCyt solution. A T2000 processor was used to prepare LBC preparations. All women underwent colposcopy/biopsy according to local protocol. Four hundred and forty-one women met the diagnostic standard criteria of the study, which was either a normal colposcopy or histopathology result. Sensitivity, specificity and positive and negative predictive values were calculated for both methods of cytology preparations.

MAIN OUTCOME MEASURES

Matched TP and conventional smears, detection of abnormality, matched biopsies, sensitivity, specificity, and positive and negative predictive values.

RESULTS

Inadequate rates for CS and LBC (TP) were 4.3% and 0.68%, respectively. In 73% of cases, the CS and the LBC preparations showed exact agreement, whereas 77% agreement was seen when comparison was made for amalgamated low grade and high grade abnormalities. Low grade cytological abnormalities accounted for 44% of LBC slides versus 37% in CS slides. High grade cytological abnormalities accounted for 22% of LBC versus 17% seen in CS cases (P < 0.001). LBC showed increased sensitivity in the detection of CIN2 or worse than CS (92% and 83%, respectively) and CS showed greater specificity than LBC (82% and 76%, respectively).

CONCLUSIONS

In high prevalence setting, LBC performed at least as well as CS. The inadequate rate was significantly lower with LBC. The numbers are too small, however, to make confident comments about increased sensitivity and negative predictive value with LBC. Larger studies are required to verify these findings.

Variability in Cytologic-Histologic Correlation Practices and Implications for Patient Safety

Context.—The Clinical Laboratory Improvement Amendments of 1988 require that laboratories perform cytologic-histologic correlation, although the optimal methods and the value of performing correlation have not been determined.

Objective.—To determine the similarities and differences in how laboratories perform cytologic-histologic correlation.

Design.—One hundred sixty-two American laboratories were sent a letter requesting copies of the materials they used in the cytologic-histologic correlation process. The returned materials were classified into the categories of forms, logs, and tally sheets. A checklist (derived from the College of American Pathologists Laboratory Accreditation Cytopathology Checklist) was developed to classify the “minimum expected” (15) and “additional” data points that laboratories collected when they performed a correlation.

Participants.—American pathology laboratories.

Main Outcome Measures.—Measures were percentage of laboratories that recorded minimum expected and additional data points and the frequency with which specific minimum expected data points were recorded.

Results.—The response frequency was 32.1%, and a total of 84 cytologic-histologic correlation materials were obtained. The only minimum expected variables recorded on forms or logs by more than 50% of laboratories were cytology case number, sign-out cytology diagnosis, surgical pathology case number, and sign-out surgical pathology diagnosis. Nine (17.3%) laboratories did not record data on forms, logs, or tally sheets. The mean number of minimum expected and additional variables recorded on forms was 6.5 and 8.7, respectively.

Conclusions.—Laboratories record data from the cytologic-histologic correlation process in a number of ways, indicating the lack of standardization of the data collection process.

Visual inspection of the cervix with acetic acid for cervical intraepithelial lesions

OBJECTIVE

Evaluation of visual inspection of the cervix with acetic acid (VIA) for screening cervical intraepithelial neoplasia.

METHODS

In this prospective study, 400 women were screened using the Papanicolaou (PAP) smear, VIA and colposcopy. Those who had positive results with any of the screening methods underwent large loop excision of the transformation zone (LLETZ). The sensitivity and specificity of each of the screening methods was analyzed.

RESULTS

The sensitivity of VIA (96.7%) was much higher than that of the Pap smear (50%), and almost as high as that of colposcopy (100%). The specificity of VIA (36.4%) was lower than that of the Pap smear (97%) and colposcopy (96.9%), resulting in high false-positive rates for VIA. Two cases of endocervical lesions were missed with VIA.

CONCLUSION

Visual inspection of the cervix with acetic acid is very sensitive for ectocervical lesions. The advantages of the VIA method are its low cost and ease of use (it can be used by paramedical workers), its high sensitivity and its immediate results (it is possible to "see and treat" at the first visit). Its main limitation is a high rate of false-positive results, which may lead to overtreatment if a "see and treat" policy is applied.

Measurement Characteristics of Anal Cytology, Histopathology, and High-Resolution Anoscopic Visual Impression in an Anal Dysplasia Screening Program

BACKGROUND

The study aims were (1) to estimate agreement between consecutive anal cytologic examinations, between concurrent cytologic examination and histopathology, and between high-resolution anoscopy (HRA) visual impression and histopathology and (2) to estimate the prevalence of severe dysplasia by concurrent cytologic category.

METHODS

Prospective study of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa-statistics.

RESULTS

Between July 2000 and September 2003, 1864 patients underwent 2947 anal cytology tests. Excluding unsatisfactory tests (6%), 642 patients had repeat cytologic evaluation and 154 had concurrent cytology tests and biopsy. Using 4-category cytology grading, kappa-agreement between the first 2 cytologic measurements was 0.36. Comparing concurrent cytology tests and biopsy, kappa-agreement was 0.36. Comparing the most severe HRA visual impression and biopsy, kappa-agreement was 0.32. The prevalence of anal intraepithelial neoplasia 3 at biopsy by concurrent cytology category was 0 (cytology normal), 21% (atypical squamous cells of uncertain significance), 27% (low-grade squamous intraepithelial lesion), and 54% (high-grade squamous intraepithelial lesion).

CONCLUSIONS

These data suggest that the reproducibility of key screening measures is moderate at best but of similar magnitude to that of other studies of anal and cervical dysplasia screening. As candidate interventions to treat or prevent precursor lesions enter clinical development, standardization and improvement of measurement methods are essential.

Video monitoring of smear-taking at colposcopy: relationship to cytology

OBJECTIVE

To investigate the reasons why cervical smears occasionally fail to reflect the underlying pathology in the cervix even when the smear is taken at colposcopy.

DESIGN

A randomised study of three different smear-taking devices.

SETTING

A colposcopy clinic.

POPULATION

Women attending the colposcopy clinic.

METHODS

A smear was taken from 172 nulliparous and 100 multiparous women at colposcopy and the procedure was monitored on a video-imaging system. The cytological findings were compared with the biopsy report in 147 nulliparous and 85 multiparous women.

MAIN OUTCOME MEASURES

Accuracy of cytology and the effect of a range of variables on the accuracy of cytology.

RESULTS

Sampling of the transformation zone was incomplete in 15% of nulliparous women and 8% of multiparous women. Univariate analysis of a range of variables including parity, type of sampling devices, completeness of sampling of the transformation zone, size of the transformation zone, size of the lesion (aceto-white area) and location of the squamo-columnar junction showed that the accuracy of cytology was influenced by all these factors except for parity and smear-taking devices. Multivariate analysis showed that the location of the squamo-columnar junction, the size of the transformation zone area, the size of the aceto-white area and the ratio of the aceto-white area to the area of the transformation zone influenced the accuracy of cytology.

CONCLUSIONS

Women with large transformation zone areas (>30.03 mm(2)) and/or small aceto-white lesions (<7.01 mm(2)) are more likely to have an inaccurate cytology reports than women with small transformation zone and women with larger aceto-white areas. A ratio of the aceto-white area to the area of the transformation zone of 0.22 or less increases the risk of disagreement between the cytological and histological findings.

Fourier transform infrared (FTIR) spectral mapping of the cervical transformation zone, and dysplastic squamous epithelium

OBJECTIVES

This paper is aimed at establishing infrared spectral patterns for the different tissue types found in, and for different stages of disease of squamous cervical epithelium. Methods for the unsupervised distinction of these tissue types are discussed.

METHODS

Fourier transform infrared (FTIR) maps of the squamous and glandular cervical epithelium, and of the cervical transformation zone, were obtained and analyzed by multivariate unsupervised hierarchical cluster methods. The resulting clusters are correlated to the corresponding stained histopathological features in the tissue sections.

RESULTS

Multivariate statistical analysis of FTIR spectra collected for tissue sections permit an unsupervised method of distinguishing tissue types, and of differentiating between normal and diseased tissue. By analyzing different spectral windows and comparing the results with histology, we found the amide I and II region (1740-1470 cm(-1)) to be very important in correlating anatomical and histopathological features in tissue to spectral clusters. Since an unsupervised, rather than a diagnostic, algorithm was used in these efforts, no statistical analysis of false-positive/false-negative results is reported at this time.

CONCLUSIONS

The combination of FTIR micro-spectroscopy and multivariate spectral processing provides important insights into the fundamental spectral signatures of individual cells and consequently shows potential as a diagnostic tool for cervical cancer.

Positive predictive value of liquid-based and conventional cervical Papanicolaou smears reported as malignant

OBJECTIVES

The predictive value of cervical Papanicolaou (Pap) smears reported as "positive for malignancy," especially those obtained by the liquid-based method, has not been adequately assessed. The objectives of this study are to determine the positive predictive value of Papanicolaou smears with features of malignancy, to compare the accuracy of Papanicolaou smears obtained by the liquid-based method to those obtained by the conventional technique in this setting, and to study the factors influencing a false-positive cytologic diagnosis of malignancy.

MATERIALS AND METHODS

Pap smears significant for malignant cytology were identified at Fletcher Allen Health Care Hospital in Burlington, VT, from May 1, 1995, to April 30, 2001. A retrospective review of the hospital records and pathology reports was performed documenting patient characteristics, the collection technique, and the final histology. An independent review of the cytology and histology was performed. The positive predictive value and false-positive rate of malignant cytology were calculated for the liquid-based and conventional Pap smear techniques.

RESULTS

A total of 472,743 Pap smears were performed during the period specified. One hundred four Pap smears were reported as positive for malignancy, yielding a prevalence rate of 0.02%. A total of 68 patients had paired cytology and histology specimens. Malignant cytology was identified in 36 smears obtained by the liquid-based technique and 32 smears obtained by the conventional technique. A true-positive result, meaning malignant cytology confirmed by the presence of invasive carcinoma on histology, was obtained in 61 of 68 (89.7%) patients. A false-positive result, meaning malignant cytology not confirmed by histology, was obtained in 7 of the 68 (10.3%) patients. The false-positive rate of malignant cytology was 8.4% for the liquid-based technique and 12.5% for the conventional technique. All 7 false-positive smears were diagnosed with high-grade dysplasia by histology. Three of the 7 patients with high-grade dysplasia had previous treatment for dysplasia, one of whom was also pregnant at the time of the smear.

CONCLUSIONS

Malignant cervical Papanicolaou smear cytology has a high positive predictive value in the setting of gynecologic and nongynecologic malignancies. Previous treatment for cervical dysplasia or pregnancy may influence the false-positive rate of malignant cytology.

Prevenção do câncer de colo do útero: um modelo teórico para analisar o acesso e a utilização do teste de Papanicolaou

Vários estudos têm apontado que a permanência das altas taxas de incidência e mortalidade por câncer cérvico-uterino deve-se à baixa qualidade e cobertura do teste de Papanicolaou, principalmente em países em desenvolvimento. Pretende-se neste artigo analizar alguns pontos relacionados às medidas de prevenção e controle do câncer cervical quanto à efetividade do teste de Papanicolaou, a lógica operacional e científica por detrás das políticas públicas de prevenção ao câncer cervical e a cobertura do teste em países norte-americanos, europeus e na América Latina. Consideram-se, ainda, os modelos explicativos que estão sendo propostos para avaliar o acesso e a utilização deste serviço, a partir da análise dos fatores associados à realização do teste de Papanicolaou descritos pela literatura. Propõe-se uma nova abordagem na investigação destes fatores, buscando a integração e interlocução de outros aspectos de cunho social, cultural e organizacional na análise do acesso e da utilização deste exame, visando um planejamento mais coerente das ações de prevenção e promoção à saúde com as necessidades e direitos das mulheres.

Real-time, high-definition, three-dimensional microscopy for evaluating problematic cervical Papanicolaou smears classified as atypical squamous cells of undetermined significance

BACKGROUND

The perceived inadequacies of the cervical Papanicolaou (Pap) smear have been attributed to sampling, screening, or interpretive errors. Within this type of cytologic preparation, there are thick cell clusters in which the cells are obscured. It may not possible to evaluate these areas by conventional microscopy. The authors clinically tested the hypothesis that high-definition, three-dimensional (3-D) microscopy based on multiple oblique illumination (MOI), with its ability to penetrate into thick areas, would be useful in evaluating problematic cervical Pap smears, particularly those diagnosed as atypical squamous cells of undetermined significance (ASCUS).

METHODS

ASCUS Pap smears and corresponding surgical biopsy specimens were evaluated prospectively using standard, axially illuminated microscopes and a new high-definition, 3-D microscope employing MOI. The Pap smears were reviewed in a blinded fashion with both types of microscopy. The rendered diagnoses were then compared with the subsequent tissue biopsies, which also were blinded, as the definitive end point.

RESULTS

It was immediately apparent that the high-definition, 3-D MOI microscope had better resolution compared with the standard microscopes. Pap smears and biopsy diagnoses were correlated significantly for MOI (P < 0.001), and there were significant improvements (P = 0.0108) in accuracy when 3-D, high-definition microscopy was compared with conventional microscopy. The authors found no statistically significant correlation between ASCUS diagnoses that were rendered by using standard microscopes compared with the subsequent biopsy.

CONCLUSIONS

Due to enhanced visualization through thick cell clusters, an increased depth of field, light penetration, and resolution, high-definition, 3-D microscopy based on MOI produced superior accuracy compared with conventional light microscopy in evaluating cervical Pap smears.

How predictive is a cervical smear suggesting glandular neoplasia?

The prevalence of endocervical adenocarcinoma and its precursors has increased, in part due to increased diagnostic awareness of these lesions. To date, limited information has been published regarding the predictive value of glandular abnormalities in cervical smears. This study details the histological follow up of 418 cervical smears showing glandular abnormality, reported in our department over a six year period from 1993 to 1998. Histological follow up was available for 395 of the 418 smears (94.50%). The overall positive predictive value (PPV) for this group of smears was 72.66% for either significant glandular or squamous pathology (at least low grade cervical glandular intraepithelial neoplasia or CIN2 on follow up biopsy), and 55.70% for significant glandular pathology alone. Examination of subcategories of abnormal glandular smear showed that the PPV increased with the degree of abnormality reported within the smears.

Institutional review of outside cytology materials: a retrospective analysis of two institutions' experiences

Discrepancy rates between original and review histopathologic diagnoses have been well-studied, and range as high as 30% in some studies. While the sensitivity and specificity rates for a variety of cytologic specimens are well-known, few data exist as to the discrepancy rates associated with in-house, second-opinion reviews of outside material. We studied the 2-yr experience of two university-based medical centers' reviews of outside cytology materials. A total of 146 cases underwent second-opinion review. The majority were fine-needle aspiration specimens obtained from the breast, thyroid, lung, and hematobiliary system. Nine cases were cervical vaginal specimens, 19 were bronchial brushes, washings, or lavage specimens, 13 were pleural fluid specimens, 5 were bile duct brushings, and the remainder were exfoliative cytologies, including those from the cerebrospinal fluid, urine, and pelvis. In all, 24 disagreements were encountered, 11 of which were considered major in that a significant change in therapy occurred due to an alteration in diagnosis, while 13 were considered minor in that a different diagnosis or subclassification was given by the consultant pathologist, but this diagnostic change did not significantly alter therapy. The overall diagnosis disagreement rate of 16% is similar to the diagnostic discrepancy rate encountered in second-opinion reviews of surgical pathology specimens. The 8% major discrepancy rate is slightly higher than that seen in similar studies of surgical pathology material.

Cervical biopsy/cytology correlation data can be collected prospectively and shared clinically

Cervical cytology (Cy) and biopsy (Bx) correlation is used by institutions for the evaluation of their cytodiagnostic capabilities as a part of overall laboratory quality improvement (QI). However, the data obtained from correlation are not routinely included in most surgical pathology (SP) reports. Our laboratory's procedure is to include the correlation of the patient's previous (most recent) cytology smear in the surgical pathology report of all/any gynecologic surgical pathology specimens. We reviewed this process for the time period between July 1998-June 1999. Any noncorrelating cases were assigned a correlation review code by the reviewing cytopathologist: major Cy diagnostic error (DE1), minor Cy diagnostic error (DE2), Cy sampling error (Cy SE), or biopsy sampling error (Bx SE). Of 3,486 cases reviewed, 3,229 cases were satisfactory for correlation studies. Concordant results were found in 86.9%. Cy DE1 due to either Cy screening or interpretation errors or both were found in 0.2% (n = 7) of all cases, while Cy DE2 due to the same were found in 1% (n = 32). Bx SE accounted for discrepancies in 6.8% (n = 220) of all cases, while 5.1% (n = 164) of the total cases were discrepancies due to Cy SE. Follow-up Bx was available in 97.2% (n = 214) of the Bx SE, and showed 16.4% (n = 35) to be major discrepancies and 83.6% (n = 179) to be minor discrepancies. Cervical Cy/Bx correlation is useful for the evaluation of a laboratory's QI. It is also useful for the identification of either Cy or Bx SE. While QI data exist as "internal use only" documents, SE data (as part of the CC (correlation comment) included in SP reports) are vital to a specific/given patient. Bx SE was identified in 6.3% of our patients, indicating a possible need for rebiopsy. This type of QI data may be shared clinically, and may direct the management for maximum diagnostic and patient benefit.

Clinical perception of disease probability associated with Bethesda System diagnoses

The degree to which clinical perceptions of Papanicolaou smear sensitivity contribute to patient mismanagement is uncertain. A voluntary, anonymous questionnaire was mailed to 350 obstetricians/gynecologists (OGYNs) and 350 other primary care providers (PCPs) located in Pennsylvania or Ohio. The clinicians estimated the probability of no disease, dysplasia, and invasive carcinoma for 1 of 7 Bethesda System diagnoses. Differences in probability estimates between provider types and between the clinicians and medical literature data were measured. The response rate was 22.7%. Compared with published values, clinicians estimated similar disease probabilities for many diagnoses. However, for some diagnoses, the probability estimates differed considerably from published values (e.g., overestimation of dysplasia and invasive carcinoma for benign diagnoses and underestimation of dysplasia for some dysplasia diagnoses), and such errors could contribute to patient mismanagement. OGYNs generally were more accurate in probability estimates than PCPs. Methods to convey more accurately these diagnostic disease probabilities should be examined.

Performance of cytology and colposcopy in diagnosis of cervical intraepithelial neoplasia (CIN) in HIV-positive and HIV-negative women

As part of an extensive multi-institutional DIANAIDS-HIV-HPV-SIL project run in Italy (co-ordinated by ISS), the present study compares the performance (sensitivity, specificity, agreement) of routine cervical smear cytology with that of colposcopy in the detection of histologically-confirmed CIN lesions in 37 HIV-positive and 21 HIV-negative women, belonging to the DIANAIDS cohort of 459 women. All women were subjected to a cervical smear, colposcopy and biopsy, making possible the pairwise comparison of these techniques. In the whole series of HIV-positive and HIV-negative women, cytology had a sensitivity of 86.9% and specificity of 83.3%, the sensitivity of grade 2 abnormality on colposcopy against histology being 82.6% and specificity, 33.3%. No statistically significant difference was observed in the performance of Pap smears between the HIV-positive and HIV-negative women. The sensitivity of cytology was 89.7% vs 82.4% and the specificity, 75% vs 100%. For colposcopy, the sensitivity was 79.3% vs 88.2% and the specificity, 75% vs 50%. These data suggest that cervical Pap smear cytology is a highly sensitive and specific diagnostic tool in the clinical monitoring of lower genital tract pathology in HIV-positive women. Colposcopy, on the other hand, proved to be a somewhat less accurate diagnostic tool in these women.

Role of fine-needle aspiration cytology in nonpalpable mammary lesions: a comparative cytohistologic study based on 308 cases

We retrospectively evaluated the accuracy of fine-needle aspiration cytology (FNAC) in nonpalpable breast lesions detected by imaging techniques between 1995-1997. A total number of 308 lesions was investigated: 273 had been studied by means of either FNAC obtained under ultrasound (175 cases) or stereotactic guidance (98 cases). The overall sensitivity rate was 87.8%; specificity was 95.3%; the positive predictive value was 76.6%; the negative predictive value was 97.8%. Our results confirm that FNAC is quite effective in the approach to patients with nonpalpable breast lesions. It is particularly accurate in diagnosing malignancy, although a lower yield may be encountered in tumor types producing a desmoplastic stroma (tubular carcinoma, infiltrating lobular carcinoma) or in noncomedonic in situ ductal carcinoma. Discrepancy between a suspicious cytology and a negative histology is more frequent with benign lesions usually because of sampling mistake or technically inadequate smears. In particular, when smears are adequate, FNAC safely assists in ruling out the malignant lesions.

Quality management in gynecologic cytology using interlaboratory comparison

OBJECTIVE

To describe a comprehensive integrated laboratory quality management plan for gynecologic cytology.

DESIGN AND SETTING

Cytopathology laboratory performance monitors with interlaboratory comparison.

RESULTS

Utilizing College of American Pathologists Q-Probes studies, the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology, and other published data, a quality management program for gynecologic cytology involving diagnostic statistics, screening limits and competency assessment, retrospective rescreening, real-time rescreening, cytology-biopsy correlation, follow-up of patients with abnormal cytology results, turnaround time, examination of unknown slides (survey programs), and new technology is described.

CONCLUSION

Regular coordinated monitoring of performance, with longitudinal and interlaboratory comparison utilizing the methods described, provides an opportunity to optimize gynecologic cytology service.

Accuracy of Pap tests reported as CIN I

Papanicolaou (Pap) tests reported as CIN I (cervical intraepithelial neoplasia, grade 1) may be subject to laboratory misclassification because of screening and interpretative errors. A peer-groupC consensus review was conducted to measure the misclassification rate of Pap tests reported as CIN I and to analyze the undercalled and overcalled tests for due cause. Four hundred and forty-nine Pap tests originally reported as CIN I were independently reviewed twice by a panel of four pathologists, and disagreements were resolved by consensus review. Results were based on the original screening for the first review and, following the removal of those markings, were based on a second, independent rescreening for the second review. A review result of low-grade squamous intraepithelial lesion (LSIL) and atypical squamous cells of undetermined significance (ASCUS) favoring LSIL was equated with the original CIN I result. Final classification was based on the second consensus review. Misclassified tests were categorized as screening or interpretative errors, based on a comparison of the review classifications. LSIL and ASCUS favoring LSIL were reported in 85.1% and 73.9% of the first and second reviews, respectively. In the final classification there were 362 (80.6%) LSIL and ASCUS-LSIL and 87 (19.4%) misclassifications: 31 (6.9%) undercalls and 56 (12.5%) overcalls. Screening error accounted for 35.5% of undercalled tests, and the remainder were interpretative errors, as were all those overcalled. In this study, Pap tests reported as CIN I were subject to misclassification because of a laboratory error in 19.4% of tests. Reductions in screening and interpretative errors were identified as mechanisms for improving accuracy. Diagn. Cytopathol. 1999;21:129-136.

ThinPrep Pap Test: performance and biopsy follow-up in a university hospital

BACKGROUND

The ThinPrep Pap Test (TP), a liquid-based cervical cytology preparation, was approved for use in the U.S. in 1996. The purpose of this study was to compare TP performance and biopsy follow-up studies with a similar population of high risk patients sampled by conventional Papanicolaou (Pap) smear (CS).

METHODS

Diagnostic and specimen adequacy interpretations for 2727 TP direct-to-vial Pap tests from a high risk university hospital practice were compared with 5000 CS preparations from the same physicians taken 1 year previously. Biopsy follow-up studies for the categories of squamous intraepithelial lesion (SIL), carcinoma, and atypical squamous cells of undetermined significance (ASCUS) for each time period and technique were contrasted.

RESULTS

The SIL/carcinoma detection rate increased from 7.7% to 10.5% (P < 0.01) and the ASCUS rate decreased from 12.5% to 6.9% (P < 0.01); the percentage of satisfactory but limited specimens decreased from 19.4% to 10.5% (P < 0.01). Low grade SIL cases increased by 57% (P < 0.01) whereas the 26% increase in high grade SIL cases was not statistically significant. Greater than 90% of ungraded SIL, high grade SIL, and carcinoma cases had abnormal biopsies by both the TP and CS methods. The number of biopsy-confirmed high grade dysplasias and carcinomas was similar in the two groups. A low grade SIL detected by TP was less likely to have an abnormal biopsy (70% vs. 85% for CS). Nevertheless, the 57% increase in low grade SIL diagnoses by TP resulted in more TP patients with dysplastic biopsy diagnoses. Follow-up studies for ASCUS cases diagnosed by either TP or CS were similar, and 21-24% of patients eventually were found to have dysplasia.

CONCLUSIONS

The TP technique appears to lead to the increased detection of low grade SIL lesions, decreased satisfactory but limited samples, and fewer equivocal specimens. No increase in biopsy-confirmed high grade dysplasias and carcinomas was found. Follow-up studies for the ASCUS category were nearly identical to those for CS.

Histology corresponding to mildly dyskaryotic smears--a study of 190 laser cone biopsied patients

OBJECTIVES

The aim of the study was to evaluate the histological outcome of laser ring biopsies in patients with one or more smears showing cytological mild dyskaryosis where punch biopsies were not performed. The possibilities of predicting histological findings of CIN 2 and CIN 3 were analyzed.

METHODS

The study comprised 190 laser ring biopsied patients with mildly dyskaryotic smears. Eighty-five patients were excluded from the initial 275 because of up- and downgrading of smears. Conization specimens and smears were reviewed by an experienced histopathologist and two experienced cytotechnicians. The histological findings were correlated to smear findings.

RESULTS

Histologically, CIN 2 was found in 60 and CIN 3 in 45 patients (31 and 24%, respectively). The incidence of histological CIN 3 was higher in those with two or more mildly dyskaryotic smears and in those dyskaryotic smears lacking koilocytic change. Mildly dyskaryotic smears without endocervical cells indicated higher incidence of histological CIN 3. The fact that 36 of 96 CIN 2 and 3 lesions (38%) involved only 3 mm or less of the mucosa might be one important explanation for the absence of representative cells in the corresponding smears.

CONCLUSIONS

Our study has shown that a mildly dyskaryotic smear is a strong indicator of CIN 2-3 histologically, especially in those cases without koilocytic cells and in those with repeatedly abnormal smears. The importance of inadequate sampling is indicated by higher incidence of histological CIN 3 in those with less than optimal smears. These findings are some of the factors to be taken into account when planning treatment strategies for this group of patients.

Comparison of the risks of cytologic surveillance of women with atypical cells or low-grade abnormalities on cervical smear: review of the literature

Minor cytological abnormalities--low-grade squamous intraepithelial lesions (LGSIL) and atypical squamous cells of undetermined significance (ASCUS)--are the most frequent abnormalities observed in smears performed in screening for cervical cancer. Surveillance through repeated smears has been proposed as an alternative to immediate colposcopy to reduce cost and avoid overloading colposcopy clinics. The aim of this review is to discuss the advantages and inconveniences of cytological surveillance of women with ASCUS or LGSIL, as reported in the literature. Cervical smears are not sufficient to establish the precise diagnosis of a lesion. In fact, the mean prevalence of normal cervices, high-grade CINs and cancers is estimated to be 58%, 7% and 0.5% for ASCUS and 34%, 27% and 0.2% for LGSIL. Cytological surveillance shows that minor cytological abnormalities regress in 28-69% of cases. In 6-9%, cytological regression masks a high-grade CIN, and a cancer may develop sooner or later in 0.30-1.12% of cases. Cancers often occur in patients temporarily lost to surveillance or in those with normal smears alternating with smears showing minor abnormalities. Strict modalities of surveillance are therefore required. The surveillance has to be carried out with smears repeated every 4-6 months for 2 years. If all smears are normal the regular screening at 3-year intervals may be resumed. On the other hand, an immediate colposcopy is recommended if a new abnormality is observed in these consecutive smears, regardless of its severity and of the time elapsed since the initial abnormality was discovered. With these recommendations in mind, cytological surveillance may slightly reduce the number of colposcopies but without reducing significantly the cost. At present, no arguments based on cost or efficacy clearly favour cytological surveillance over immediate colposcopy.

Analysis of error in calculating the false-negative rate in the interpretation of cervicovaginal smears: the need to review abnormal cases

BACKGROUND

Determining the false-negative rate (FNR) of cervicovaginal smear interpretation is a necessary step for any quality assessment and improvement program. All tests estimate the FNR, but the accuracy of these estimates varies from test to test. Two methods for determining the FNR have been proposed, specifically "seeding" of the initial screening population with smears from patients with a known diagnosis and rescreening a random sample of negative smears. However, the accuracy of neither method is known.

METHODS

A review of the literature, an analysis of the sources of error, and an estimate of their magnitude was performed for each method.

RESULTS

Seeding has a large sampling error, and more important, the FNR that this test measures does not reflect the FNR of the laboratory as a whole. Random rescreening underestimates the FNR of primary screening by the FNR of rescreening. Currently, the FNR of rescreening is not known, not measured, and may be high. Nevertheless, the FNR of rescreening and the false-positive rate (FPR) of initial screening both can be measured by rescreening abnormal cases. Knowledge of both the FNR and the FPR of initial screening allows the efficiency of cervicovaginal smear interpretation to be measured, which may be a better measure of overall accuracy than the FNR alone.

CONCLUSIONS

Random, blinded rescreening of normal and abnormal smears can more accurately measure the FNR of screening than rescreening of normal smears alone.

Cervical Cancer: Screening and Prevention of Invasive Disease

Cancer of the cervix is one of the leading causes of cancer-related deaths in women in the United States and accounts for more cancer deaths than any other cancer in third-world countries. Various screening procedures have been developed, but many issues need to be resolved for cervical cancer screening to be effective. Large segments of the population who do not undergo regular screening account for most of the patients with invasive cancers in the United States and worldwide. Allocation of resources and widespread educational programs for these target populations are needed to promote adequate cytologic screening programs and to reduce the death rate from squamous carcinoma of the cervix.